1. Field of the Invention
The present invention relates to a soldering apparatus that solders electronic components on a circuit board. It particularly relates to a soldering apparatus which has an operation mode including a production mode that solders an electronic component on a circuit board and a temperature profile mode that measures a temperature of the circuit board carried in a main body of the soldering apparatus.
2. Description of Related Art
When soldering the electronic components on a printed circuit board, a reflow soldering apparatus is generally used. Such a reflow soldering apparatus includes a conveyor conveying the printed circuit boards and a main body of the reflow soldering apparatus into which the conveyor conveys the print circuited boards. The main body of the reflow soldering apparatus is partitioned into a preliminary heating zone, a main heating zone and a cooling zone therein. The printed circuit board on which solder paste has been previously printed is first subjected to the preliminary heating in the preliminary heating zone. In the printed circuit board subjected to the preliminary heating, the solder paste is melted in the main heating zone. Next, the cooling zone cools the printed circuit board, thereby soldering the electronic components on the printed circuit board.
Thus, in the reflow soldering apparatus, it is hopeful of controlling the preliminary heating zone, the main heating zone and the cooling zone respectively according to their optimal temperature profiles. Further, it is hopeful of managing a heating temperature and a period of heating time suitably in the main heating zone so that the temperature therein does not exceed the allowable temperature limits of the solder paste, the electronic components, the printed circuit board and the like. Therefore, in the reflow soldering apparatus, a user measures a temperature profile for verifying whether or not the temperature in each of the zones of the reflow soldering apparatus is best.
The temperature profile is measured by connecting a printed circuit board mounting a thermocouple, storage medium or the like (hereinafter, referred to as “profiler circuit board”) to a printed circuit board which is subjected to the measurement (hereinafter, referred to as “printed circuit board to be measured”), carrying them into the reflow soldering apparatus with the printed circuit board to be measured being at the head of them, and measuring any changes in temperature at measuring points in each zone by the thermocouple or the like. The storage medium mounted on the profiler circuit board stores information thus obtained, and a computer reads various kinds of information out of the storage medium mounted on the profiler circuit board after the reflow processing and utilizes the various kinds of information for setting the reflow soldering apparatus. The verification is repeated while altering any heating conditions of the reflow soldering apparatus one by one until a desired result of the temperature measurement under the temperature profile at each measurement point is obtained so that any suitable reflow conditions are set.
For example, Japanese Patent Application Publication No. 2004-64002 has proposed, as a measuring method of the temperature profile, a thermal analysis method that can find out heating condition of the heating device efficiently without using any property values of an object to be heated. According to this thermal analysis method, it is possible to perform highly accurate simulation within a short time, without actually measuring the temperature profile of the object to be heated by the correction of the heat condition.